1. Field of the Invention
The present invention relates to microfluidics, and more particularly, to a microfluidic device and microfluidic system including the microfluidic device.
2. Description of the Related Art
Conventionally, a microfluidic device has structures such as a chamber storing a minute amount of fluid, a channel through which the fluid flows, a valve for controlling flow of the fluid, and various functional units receiving the fluid to perform predetermined functions thereon. A biochip is obtained by arranging the structures on a chip-type substrate and is used to analyse the performance of various assays including biologic reactions. In particular, a device that is designed to perform multiple step processes and manipulations in a single chip is referred to as a lab-on-a chip.
A driving pressure is generally required to transfer the fluid within a microfluidic device. Capillary pressure or a pressure generated by a specifically prepared pump is used as the driving pressure. A lab compact disk (CD) or a lab-on a disk is a recently-suggested microfluidic device obtained by arranging microfluidic structures on a compact disk-shaped platform and uses centrifugal force. This is referred to as a lab CD or a lab-on a disk.
Each of microfluidic devices for biochemistry reactions, which are disclosed in pages 1824-1831 and 3740-3748, Anal. Chem. Vol. 76 published on 2004, includes a valve formed of only paraffin wax, and a heater for melting the paraffin wax. However, since a quite large amount of paraffin wax is needed for closing a channel, and a heater having large capacity is required for melting the quite large amount of paraffin wax, it is difficult to miniaturize the microfluidic devices and integrate them into an existing microfluidic systems. In addition, it takes a long time for the paraffin wax to be melted, and it is difficult to minutely control a point of time at which a channel is opened.